Disazo dyestuff.



EN OFFICE. if

HUG'U SGH'WEITZER, UH ELBERFELD, AND ARTHUR ZAIBT, G1? VOHWINKEL, NEAR ZELBERFELD, GERMAN Y, ASSIGNORS TO FARBENFABRIKEN VORM. FRIEDR. BAYER 86 "C 01' ELIBERFELID, GERMANY, A CORPORATION OF GERMANY.

IJIQAZU DYESTUIFF.

No Drawing.

Specification of Letters Patent.

Application filed August 1, 1911. Serial No. 641,774.

Patented Nov. 28, 1911.

To all whom it may concern Be it known that we, HUGO SoHwErrzER.

and ARTHUR ZART, doctors of philosophy, chemists, citizens of the German Empire, 5 residing, respectively, at Elberfeld and Vohwinkel, near Elberfeld, Germany, have in-- vented new and useful Improvements in New Disazo Dyestufi', of which the following is a specification.

The present invention relates to the manufacture and production of new azo coloring matters having mostprobably the formula:

n a R meaning a naphthol sulfonic acid, such as 5-naphthol-7-sulf0nic acid or 6-naphthol-3- sulfonic acid.

The new dyes are obtained by combining the diazo compounds prepared from an aminonaphthol sulfonic acid 6. g. 2.5T, 25 1.5.7-, or 1.6.3-aminonaphthol sulfonic acid with the 5.5dioxy-2.2'-dinaphthylam1n- 7.7'-disulfonic acid:

The new dyes having most probably the 35 formula:

are after being dried and pulverized in the shape of their alkaline sa ts dark powders soluble in water; yielding upon reduction with stannous chlorid and hydrochloric acid an aminonaphthol sulfonic acid or a mixture of two aminonaphthol sulfonic acids and a compound of the formula:

dyeing cotton from reddish-violet to bluishvlolet shades which on being developed with diazotized para-nitranilin change intoshades the ,duction with stannous ch orid and fast to washing and capable of being discharged to a pure white.

The following example may further illustrate the invention, the parts being by zweightz-478 parts (2 mol.) of l-amino-G- naphthol-3-sulfonic acid are diazot-ized with 138 arts of sodium nitrite and hydrochloric acid and combined with 461 parts of 5.5'-diox -2.2-dinaphthylamin-7 .7 -disulfonic acid dntaining an excess of sodium bicarbonate. The mixture is heated and the dye is salted out with common salt, filtered oil and dried.

The new dye having most probably the pure violet fast to washing. It can be discharged to a pure white. Two different molecules of an aminonaphthol sulfonic acid can be used.

' We claim 1. The herein described new disazodyestufls having most probably the formula:

a on

which are after being dried and pulverized in the shape of thelr alkaline saltsdark powders soluble in water; ielding u on reydrochloric acid aminonaphthol sulfonic acids and a compound of the formula:

dyeing cotton from reddishviolet to bluish- 0 violet shades which on being developed with diazotized para-nitranilin change which is after beingdried and pulverized in the shape of its so um salt a dark powder soluble in concentrated sulfuric acid with a reddish-blue coloration; yielding upon reinto' shades fast to washing and capable of beingduction with stannous chlorid and hydrochloric acid 1.6.3-amin0naphthol sulfonic acid and 6.6-diamino-5.5'-di0xy-2.2-dinaphthylamin-7.7-disulfonie acid; dyeing cotton violet, which shade after being developed with diazotized para-nitranilin is a. pure violet fast to washing which can be discharged to a pure white, substantially as described. In testimony whereof wehave hereunto set our hands in thepresence of two subscribing witnesses.

HUGO SCHWEITZER. [1..s.] ARTHUR ZART. [L.s.] Witnesses:

CHAs. J. WRIGHT, ALBERT F. NUFER. 

